Fire Forged Friends / Real Life

• The Spartans encouraged soldiers to have a good friend so that they'd fight harder to protect them. And if they died, hopefully they'd go Ax-Crazy in a quest for vengeance.
• The Thespians refused to retreat from the Battle of Thermopylae, fighting alongside the Spartans in their final stand. The Spartans marveled at this; Spartans were raised as warriors and expected to lay down their lives on command, but the Thespians were volunteer soldiers, mostly farmers and tradesmen. The Spartans saw the Thespian's willingness to sacrifice themselves as a kind of courage beyond even their own and were very proud to have such allies in their last moments. The world has not forgotten.
• The Sacred Band of Thebes consisted of 150 pairs of male lovers under the theory that a man would fight harder in the presence of his lover, so as not to be disgraced. The Sacred Band was tough enough to win repeated encounters with the Spartans but was ultimately defeated at the Battle of Chaeronea in 338 BCE (read: killed to the last man) by a force led in part by a young Alexander the Great in his first appearance as a military commander.
• Centurions Lucius Vorenus and Titus Pullo. You know, the pair who became incarnated in HBO's Rome series, except Titus Pullo got demoted to a mere career legionary. In Real Life, an incident is documented in Gaius Julius's memoirs of his Gallic ventures, where the two men who were fierce rivals ended up fighting off a large group of enemies, taking turns to rescue each other, to the cheering of the legion.
• One of the reasons of the Unification of Germany and the formation of the North German Confederation was that all the northern German countries banded together to fight the southern German countries during the Austro-Prussian war, and ultimately found out that they were far more alike than they were different.
• Although not a life-threatening situation, the cohesion formed by working to achieve superordinate goals (a superordinate goal is a desire, challenge, predicament, or peril that both parties in a conflict need to get resolved, and that neither party can resolve alone) was the key of the third phase of the Robber's Cave Experiment, information can be found here, and here.
• LA Lakers basketball players Kobe Bryant and Pau Gasol. Their friendship was forged by playing basketball together in the NBA but was most apparent when they were opponents in the final match of the 2012 Olympics- Kobe as captain of the US team and Pau as superstar of Spain's team. After the US won, the two immediately gave each other a long, tight hug.
• Louisiana Senator Judah Benjamin challenged Senator Jefferson Davis to a duel on the Senate floor over a perceived insult. The men worked out their differences without violence and became friends. When the South seceded, Confederate President Davis appointed Benjamin to three different cabinet positions in his government. Benjamin thus became the first Jewish cabinet member in a North American government.
• U.S. stealth fighter pilot Dale Zelko was shot down by Yugoslav missile operator Zoltan Dani during the Kosovo War. They became good friends after the war ended.
• A significant part of military training is to get recruits into this mindset, often by having their instructors play the role of mutual opponent.
• A lion, tiger, and bear^note Oh my! were under the care of an abusive drug dealer when they were cubs. After they were rescued, they proved to be inseparable and continued to live and play together for well over a decade until the deaths of the two big cats.
• John Isner and Nicolas Mahut played the longest Wimbledon match ever in 2010, taking over 11 hours stretched across three days to finish their first-round match (Isner won 4-6, 6-3, 7-6, 6-7, 70-68). The fifth set alone (eight hours) would have broken the previous match length record. They met again in the first round the very next year, and BBC coverage showed that they had become very close friends after their marathon match.
• Stephen Colbert admitted he didn't like Jon Stewart when the latter first began hosting The Daily Show in 1999, but they've long-since become friends.
• Boxers Micky Ward and Arturo Gatti were described as "united by all that damage they had done to each other", first bonding in the hospital after their second fight (out of three).
• A Spanish proverb goes, "It is good to have friends, even in hell."
• Keith Olbermann argues in this video that this happens with sports teams and the unique bond among members of sports teams is part of the reason why gay slurs are so prevalent in sport, as men are not always able to understand those feelings.
• While The X-Files had protagonists Mulder and Scully engaging in Belligerent Sexual Tension amidst the personality conflicts, in real life, David Duchovny and Gillian Anderson were constantly on each other's nerves, not helped by grueling shoots (in Anderson's words, “I think the grind of working every single f——— day, 17 hours a day, with each other, in those circumstances, just took its toll."). That being said, once the show ended, they actually became friends.
• During the 1980s AIDS epidemic, many LGBT activists like Larry Kramer initially hated Dr. Anthony Fauci due to his ties to the homophobic Reagan administration and him erroneously stating that routine social contact could spread AIDS. However, unlike many of his peers, Fauci reached out to the LGBT patients to understand their suffering and to develop new treatment options. Over time, many in the LGBT community warmed up to Fauci with Kramer calling him "the only true and great hero" during the AIDS epidemic.
• Both Simon Cowell and Paula Abdul will freely admit that they genuinely despised each other for the first two seasons of American Idol — it wasn't a flirty act for the cameras, the fights were very real and Simon has said that only maybe 10% of their fights ever made it to air. But by the time the third season started, something "clicked" and the two became truly close both on-camera and off, with Simon noting that they truly do love each other now. (There's still plenty of squabbling, though.)
  Simon: ...she and I are good friends, and will remain good friends. And you don't make many friends in this business, to be honest with you. People say they are, but they're not. But she — she's genuinely a good friend.

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